FHRs and the Future of Nuclear Energy

Transcription

1 FHRs and the Future of Nuclear Energy Presented to DOE FHR Workshop At Oak Ridge National Laboratory Sept , 2010 By Sherrell Greene Director, Nuclear Technology Programs Oak Ridge National Laboratory

2 Presentation Overview Nuclear energy success criteria the Five Imperatives of Nuclear Energy FHR distinctives FHRs as enablers of the Five Imperatives of Nuclear Energy 2 Managed by UT-Battelle

3 April 2010 DOE Nuclear Energy Roadmap establishes four objectives Develop technologies and other solutions that can improve the reliability, sustain the safety, and extend the life of current reactors Develop improvements in the affordability of new reactors to enable nuclear energy to help meet the Administration's energy security and climate change goals Develop sustainable nuclear fuel cycles Understand and minimize the risks of nuclear proliferation and terrorism 3 Managed by UT-Battelle

4 The Five Imperatives of Nuclear Energy define success 1. Extend life, improve performance, and sustain health and safety of the current fleet Abundant Nuclear Energy 2. Enable new plant builds and improve the affordability of nuclear energy 3. Enable the transition away from fossil fuels in the transportation and industrial sectors 4. Enable sustainable fuel cycles 5. Understand and minimizing proliferation risk 4 Managed by UT-Battelle

5 FHR s combine attributes and technologies of several different reactor types MSRs Fluoride Salt Coolants Structural Materials Pump Technologies FHRs GCRs TRISO Fuels Structural Materials Brayton Power Conversion LWRs Water/Air-tolerant Coolants Integral Primary Coolant Systems SFRs Low Primary Pressures Hot Refueling Technologies 5 Managed by UT-Battelle

6 Four FHR concepts have been developed in U.S. PB-AHTR (410 MWe)* AHTR (1235 MWe)* SmAHTR (125 MWt / 50 MWe) 6 HEER (1000 MWt) AHTR = Advanced High Temperature Rx HEER = High Efficiency and Environmentally Friendly Nuclear Rx PB-AHTR = Pebble Bed Advanced High Temperature Rx SmAHTR = Small Modular Advanced High Temperature Rx Managed by UT-Battelle

7 The potential benefits of FHRs stem directly from fundamental materials characteristics Coolant T melt (ºC) T boil (ºC) Density (kg/m 3 ) Specific Heat (kj/kgºc) Volumetric Heat Capacity (kj/m 3 ºC) Thermal Conductivity (W/mºC) Kinematic Viscosity (10 6 m 2 /s) Li 2 BeF 4 (Flibe) NaF-40.5ZrF LifF-37NaF-37ZrF LiF-31NaF-38BeF NaF-92NaBF Sodium Lead Lead-Bismuth <0.1 Helium, 7.5 Mpa Water, 7.5 Mpa Managed by UT-Battelle

8 The principal challenges of FHRs also stem from fundamental materials considerations Coolant T melt (ºC) T boil (ºC) Density (kg/m 3 ) Specific Heat (kj/kgºc) Volumetric Heat Capacity (kj/m 3 ºC) Thermal Conductivity (W/mºC) Kinematic Viscosity (10 6 m 2 /s) Li 2 BeF 4 (Flibe) NaF-40.5ZrF Design Challenges: 26LifF-37NaF-37ZrF LiF-31NaF-38BeF High coolant mel6ng temperatures Code- qualified compa6ble high temp. metals Maintenance of salt chemistry / purity Wet refueling at high temperature 8NaF-92NaBF Sodium Lead Lead-Bismuth <0.1 Helium, 7.5 Mpa Water, 7.5 Mpa Managed by UT-Battelle

9 2004 ORNL analyses* indicate cost of large FHRs can be lower than GCR and SFR power systems Abundant Nuclear Energy FHR Concept AHTR- IT (1145 MWe, 800 C T cout ) AHTR- VT (1300 MWe, 1000 C T cout ) Frac5on of S- PRISM Cost (1681 $/kwe) Frac5on of GT- MHR Cost (1528 $/kwe) Cost advantages: Thin- walled vessels and piping More compact reactor and primary coolant loops Smaller confinement/containment systems High opera6ng temperatures and thermal efficiencies * Ingersoll et al., Status of Preconceptual Design of the Advanced High-Temperature Reactor (AHTR), ORNL/TM-2004/104, May Managed by UT-Battelle

10 Achievement of Imperative 3 depends on our success in delivering nuclear process heat for many applications Abundant Nuclear Energy 10 Managed by UT-Battelle

11 Working temperatures of fluoride salts are well suited for variety of process heat applications Abundant Nuclear Energy NaF-ZrF 4 ( ) LiF-BeF 2 (67-33) LiF-NaF-KF ( ) RbF-ZrF 4 (58-42) NaF-BeF 2 (57-43) Melts Boils Electrolysis, H 2 Prod., Coal Gasification Steam Reforming of Nat. Gas & Biomass Gasification Cogeneration of Electricity and Steam Oil Shale/Sand Processing Petro Refining Managed by UT-Battelle Temperature (C)

12 FHR salt coolant heat transfer technologies were successfully demonstrated in MSRE for > 26,000 hr Abundant Nuclear Energy Molten Salt Reactor Experiment ( ) MSRE LiF-BeF2 Secondary Coolant Loop 12 Managed by UT-Battelle 600 C LiF-BeF2 / Air Blast Radiator

13 FHRs incorporate many attractive attributes for high-temperature process heat applications Coolant (Reactor Concept) High Working Temp a High Volumetric Heat Capacity b Low Primary Pressure c Low Reac5vity With Air & Water d Water (PWR) # # Sodium (SFR) # Helium (GCR) # # Salt (AHTR) Abundant Nuclear Energy a FHR system working temperature functionally limited by structural materials capabilities b High coolant volumetric heat capacity enables constant temperature heat addition / removal (ηc = 1 T C /T H ~ Carnot cycles), compact system architectures, and reduces pumping power requirements c Low primary system pressure reduces cost of primary vessel and piping, and reduces energetics of pipe break accidents d Low reactivity with air and water reduces energetics of pipe break accidents 13 Managed by UT-Battelle

14 FHRs can implement or enable all three fuel cycle classes Once-Through Standard once-through U fuel cycle similar to NGNP / GCR fuel cycles Once-through Th fuel cycle Modified Open Deep Burn similar to deep burn gas reactor fuel cycle U-Th fuel cycles Full Recycle Modified Open Cycle tier of multi-tier Full Recycle 14 Managed by UT-Battelle Abundant Nuclear Energy

15 FHRs have desirable nonproliferation attributes Abundant Nuclear Energy Qualitative comparative analysis: Better than LWRs and SFRs TRISO fuel more difficult to reprocess than LWR and fast reactor fuels FHRs have lower fissile inventory than SFRs Equivalent or better than gas cooled reactors Similar TRISO fuel (U; Th; or Deep Burn U,Pu,Np) Additional value of solidified salt coolant as barrier to fuel access? Systematic examination of FHR proliferation attributes is needed. 15 Managed by UT-Battelle

16 FHRs show much promise as enablers of the Five Imperatives of Nuclear Energy 1. Extend life, improve performance, and sustain health and safety of the current fleet 2. Enable new plant builds and improve the affordability of nuclear energy 3. Enable transition away from fossil fuels in the transportation and industrial sectors 4. Enable sustainable fuel cycles 5. Understand and minimize proliferation risk 16 Managed by UT-Battelle

17 17 Managed by UT-Battelle Summary FHRs show much promise as enablers of the Five Imperatives of Nuclear Energy Much work is needed A balanced FHR R&D strategy is required System concept development should: Identify optimal system architectures and technologies for differing applications Enable improved cost estimates Enable fuel cycle and non-proliferation assessments Inform technology and component R&D priorities FHR technology development should: Address key base technologies: coolants, materials, fuels, and I&C Address key component technologies: heat exchangers, pumps, valves Leverage ongoing NGNP and GCR R&D